Azo dyes.



UNITED. srarns PATEN FFICE.

HUGO SCI-I'WZEITZER AND ARTHUR ZART, OF ELBERFELD, GERMANY, ASSIGNORS TO FARBENFABRIKEN VORM. Fl-HEDR. BAYER & (10., OF ELBERFELD, GERMANY, A

CORPORATION OF GERMANY.

No Drawing.

To all whom it may concern:

Be it known that we, HUGO Sci-nvnrrzisn and ARTHUR ZART doctors of philosophy, chemists, citizens Oi the German Empire residing at Elberfeld, Germany, have invented new and useful Improvements in New Azo Dyes, of which the following is a specification. I

The present invention relates to the manufacture and production of new azo coloring i'rmtters having most probably the formula:

amin-7.7-d'isu lfonic acid mamas-(W 3 H H The new dyes are after being dried and is in the shape of its sodium salt a dark pow der which is easily soluble in water with a blue coloration and which is soluble in concentrated sulfuric acid with a greenish-blue coloration. Upon reduction with stannous chlorid and hydrochloric acid it is split up into 6-alnino 5.5 dioxy 2.2 dinaphthylamin-7.7'-disulfonic acid, lA-naphthylenediamin-7-sulfonic acid and paraphenylenediamin sulfonic acid. It dyes cotton greenish-blue. The shade after being developed Specification of Letters Patent.

Application filed December 9, 1911. Seria1 No. 664,860.

AZO DYES.

Patented Sept. 10, 1912.

pulverized in the shape of their alkaline salts dark powders soluble in'w'ater; yielding upon reduction with starinous chlorid and hydrochloric acid, an aromatic amin, a diam in and a compound of the formula:

SOzH

dyeing cotton from violet to greenish-blue shades which on being developed with diazotized para-nitranilin change into shades fast to washing and capable of being discharged to a pure white.

The following example may further illustrate the invention, the parts being by weight 452 parts (1 mol.) of the monoazo dye: para nitro ortho sulfobenzene azo- .l-naphthylaminJ-sulfonic acid are diazotized with 69 parts of sodium nitrite and hydrochloric acid and combined with 4-61 parts of the 5.5'-'dioxy-2.2'-dinaphthylamin- 7.7 disulfonic acid containing an excess of sodium bicarbonate. The mixture is heated and thedye is salted outwith common salt,

' filtered off and dried.

The new dye having most probably the formula:

oar

with diazotized para-nitranilin is bluish-violet fast to washing. It can be discharged to a pure white.

Other aminoazo compounds may be used c. g. such obtained from anilin, para-chloroarilin-orthosulfonic acid, meta-xylidinortho-sulfonic acid, 2-naphthylamin-4L8- disult'onic acid 011 thc one hand and l-naphthylamin-Y-sulfonic acid, anilin, orthoor meta-toluidin para-xylidin, 'cresidin, alphanaphthylamin on the other hand.

We claim: 1. The herein described new azo dyestuffs having most probably the formula:

(ill

R meaning an axe compound being free from amino and oxy groups which are after being dried. and pulverized in the shape of their alkaline salts dark powders soluble in Water, yielding upon reduction with stannous chlorid and hydrochloric acid an aromatic amin, a diamin and a compound of the formula:

on H dyeing cotton from violet to greenish-blue shades which on being developed with diazotized para-nitrani'lin change into shades fast to Washing and capable of being discharged to a pure white, substantially as described. 2. The herein described new dyc haying most probably the formula:

which is after being. dried and pulverized in .the shape of its sodium salt a dark powder soluble in concentrated sulfuric acid with a greenishbluc coloration; yielding upon reduction with stannous chlorid and hydrochloric acid (3-amino-5.5 -dioXy-2.2-dinaphthy] amin-LW-disul fonic acid, para-phenyleiiedianiin sulfonic acid and lA-naphthylenediamin-7-sulfonic acid; dyeing cotton greenishblue which shade after being developed with diazotized para-nitranilin is HUGO SCHWEI"ZER. [1. 5.] ARTHUR ZART. [1. 3.] Witnesses HELEN Norm, A. NUFER. 

